Safety inclosed fuse.



W. D. LIGON.

SAFETY INCLOSED FUSE. APPucATIoN min :UNE 21.19l5A I l. l

af v

Patented Apr. 22, 1919.

UNITED STATES PATENT OFFICE.

UQII'JIA'ISII4 D. LIGON, F MONTCLAIR, NEW JERSEY.

SAFETY IN CLQSED FUSE.

To @ZZ lwhom tlmag/ concern.'

Be it known that I, IILLIAM D. LIGON, a citizen of the States, and residimg.- at Montclair; in thezcounty of and. State oiiNfew Jersey. have.' invented,` newand' use-A ffulflmprovements in Safety Iinclosedf Fuses, of' which the following; is a specification.

retofore safe inclosed fuses have yusaally: been inclrosedr 1n: a4 casingl and' surround.- ed witlra material andl the fuse linie on wir-er solderedf to terminals or the end.

caps, thus renderingrit diiiculxt to.` readilyI replace the: fuse-'link when rupturedf by: the; passage of an excessives electric current;

` The ccnstructiom of-fremowrable safety inf. closed;4 fuses past has not made pcsv sible the. limiting oai the sizei off f'usef mires onstrips extendiingibetween the intemiahter-` minaxlsY by means; not easily altered; and# for thismeasom suhhw. fuses-calmes be; said to fhsivei a fixedlm'. deiiniteratingz AMy'r invention. relates: to impnovement in safety inclosed :fusesn` and'concerns. the comy bination andi constructions of the terminalsJ mithmthe'casiii through which the fusibles elementfis passe 1 before olningi-a substan-1 tiaiil contact with the exterior rendy termina-ls oacoxmeetionsa w' A Ii bawediscovemd lthaztAA such` diiilculties` as above: reerreulotogane: best etim-inatedrby ata. taclringmhe temnmils: han the cesingand;

sof constructing sameasto insure-against the:v

enlargementofthei hola: or aperture formed: or made tot recei-vea fuse wiref or strip.` ofA largeri diimenxfiionsl than thosef for. which the fusel' casingl or` body is designed.` .M y irn. provementsr facilitate: the', proper ad] usment o the fuse wire :or` llink when renewing the blown fuse elements.

l obtain thesei objectsbyJ the construction shown and illustrated in the accompanying drawings, in which- Figure, 1 and Fig. 4 are cross sections of`t'lie'ent'ire fuse. Fig. 2 is an end View of terminal 5; Figi 3f..is:amend view of terminal 6; Fig; 4 isla longitudinal section of a modified inem. offniny invention; Fig. 5 is an end elevation of the fuse shown 4;'Eigi' 6fis identical? withl the right hand cnd of Fig. 4 except that the dislt'er# SpecificationI of Letters Patent.

'the' fuseA elements on each Patented Apr. 22, 1919.

Applicationled'lune 21, 1915: Serial No. 35,488.

minal 6' is pro-vided with perforations 7, throughl which. the elements l extend. The terminal` 5 is provided with openings for side of its plate 3, which openings terminate in a cone-shaped hole or month et, the larger end of which is of substantially the same internal diameter as the internal diameter of the casing 2 and concentric therewith. so aslto act 'for a guide for the forward ends of the elements 1 when they are fed' `into. the casin through the holes 'Z' guiding them. towar I the openings on. eachside of theplate 3. The ends of the fusible elementsrare secured to the terminals 5-and (if by' screws & Surrounding the ends of? the, casing) `are caps 9 which arelprovided' writhisuitable slots so thattheycan'be passed over the blades 3, which constitute eaterr'lal-lternriinalsiY These ca s are secured tothe casing by screws 11. f e-inner ends of the blades 3 are held in slots 12 in the tei'rminalisl` 51 and' 6; The terminals 5 and" 6 are heldf Within the casing. The casingcontains the: lboselilling. ordinarilyusedl` in inclesed. iiuses..l Adjacent to the terminals- 6 amd preferably in 4close'v roximity thereto is a disk 15 having'holesw ich register with the holes 7.' It is preferably of'hardened steel or substance dilicultrtounachinel ori drill' and may be :brazedI orfsclc'leredY :to `'the te'rfminallv'. Its holes arecalibrated so asto determine the' size ofi the; usible elements which can' be inserted in the casing'.`

In order to renew the fusible elements in the fuse when blown, the caps' 9- are first' removed. IPhe. screws 82 are then loosened and the unburned portions of the fusible elements are drawn outward; 'New fusible elements are. then introduced through the holes 7 in the terminal 6, the conesshapedf mouth serving: to guide their forward ends-so that they are easily passed thronghthe openings inthe terminarl. When the4 fusible elements have 'been passed throng-.h the casing in this manner, their forward' and' rearends are clamped underneath the screws 8. The caps 9 are then restored to their places.

In the modificationshownl in Figs4 to 6, which is more applicable for a smaller sized fuse. l is the fusible clement; 2 is the casing 5^ and 6^ are terminals secured in the ends of the Casin The terminal 6^ has a perforation 7 am has adjacent to it a steel or other hardened disk l5 having a calibrated perforation registering with the perforation 7. The terminal 5^ has a concshaped opening 4. Each of these two terminals has integral therewith a projection 13 having a cross-cut therein crossing the hole 7. These projections are screw-threaded. The fuse is provided with caps 9^ which extend down over the ends of the casing and are provided with holes having screwthreads adapted to engage with the screwthreads upon the projections 13 so as to hold the caps in pla/ce and also to clamp the ends of the fusible element against the terminals 5^ and 6^. In this modification, when it is desired to renew the fusible element, the caps 9^ are unscrewed and the unburned portions of the fusible element drawn outward. A new fusilble element is then fed inward through the hole 7 until its forward end, guided y the cone-shaped mouth 4, passes through the opening in the terminal 5^. The ends of the fusible element are then bent downward in the cross-cuts 14 and twisted around the projections 13, after which the caps 9^ are screwed into place so as to securely clam the ends of the fusibleelement. In thisform the caps constitute the external terminals. It is to be noted that the fusible element is of such a size that all portions of it will pass through the perforatlons in the terminal 6^ and lthe plate 15.' i

' With the construction above described, .the fusible element can be easily renewed' without any substantial loss of the filling, and, furthermore, it is impossible to insert a fusible element of a greater capacity than the fuse casing is desigualY to carry.

In thesespeciications the term internal terminal" relates to terminals 4within 'the fuse casing as 5, \5^,\6, and 6^. External terminal refers to cup-shaped caps-9' and 9^, blades or connections 3, extending lpartially vithin the fuse and partially wit out the use.

In the foregoing I do not limit myself in any way to the shape of the particular parts. From the foregoing the operation of my safety inclosed use is easily understood. When the fusible element 1 as been ruptured by an excessive electrical current the remaining parts may be easily removed by unscrewing the terminal 9^ in Figi 4, or loosening the screws 8, in Fig. 1. he renewin of the fusible element is easily accomplished b assing the fuse wire or strip through the o e 7, cone-shaped aperture 4,

Copies of this patent may be obtained for ve cents each, by addressing the and formed under the screw heads 8, or caps 9 and 9^. The holes or apertures 7, are made to receive a fusible element or elements representing the maximum capacity of the casing, and in order to load the fuse to a greater capacity it is necessary to enlarge the hole or aperture 7; which operation is made difficult by the use of metals not easily drilled or machined.

Having thus described my invention, I claim- 1. In an inclosed safety fuse, the combina,- tion of a casin a terminal at one end having a perforation, a terminal at the other end havin a perforation, a fusible element all parts o which can pass through said first perforation and whose forward end can pass through said second perforation, the inner end o said second perforation daring so as to be of approximately the same diameter as the internal diameter of said casin and act as a guide for the forward end o? said element when inserted through said first perforation, said terminals belng4 'provided with screw-threaded external projections havingicross-cuts for .the ends of said Aelement, and caps inclosin'grthe ends vo'f-.said casing and having'. screw-threaded openings making engagement with l'said x projections, and clamping the ends of said-element.

l 2.- In an inclosed safety-'ifuse,.the combination of acasing, a terminal at one end havin a perforation, 'a-terminal atthezotheren having a perforation,= a fusiblmeleinent all parts of which can passithrough saidwrst perforation and whose forward end can pass through said second perforationoimeans for securing the ends of said tfusible element the inner4 'end Vof 'said second' perforation .'ring so as to be of approximately. the saine diameter as the .internaldiameter ofsaid casing and act as a guide `-for the forward end of said element when inserted through said first perforation, and a hardened steel disk within said casin and adjacent to said first terminaland havin the inner surface of a calibrated hole in a inement with said perforation therein. 19Signed by me this 5th day of February,

1 -W1LLiAM D. LIGoN. Witnesses:

G. A. BmcKMonr.,

E. P. MoN'rAoUn.

Commissioner of Patents.

Washington, D. O." 

